Why are the temperatures different in four seasons?

First, in the process of revolution, the direction of the earth's axis remains unchanged. Second, the earth axis is always inclined (the angle between the earth axis and the orbital plane is about 66.5? (3) For the above two reasons, the direct point of the sun runs between the Tropic of Cancer in the revolution. When the direct point of the sun moves to the northern hemisphere, the solar altitude angle in the northern hemisphere increases and the solar heat in the northern hemisphere increases. The northern hemisphere is dressed in spring and summer, but it is known that when the direct point of the sun moves to the southern hemisphere, the solar heat in the northern hemisphere decreases, and the northern hemisphere is dressed in autumn and winter. (The seasons in the northern hemisphere are opposite) This is the four seasons on the earth. The hot and cold changes of the four seasons are generally related to the movement of the direct point of the sun. If further analysis is needed, it is directly related to the solar altitude angle. What is the altitude angle of the sun? The sun is far away from us, so we can regard the rays of the sun as parallel rays. The angle between these parallel rays and the ground plane is the solar altitude angle, and the earth is round. If you look at the picture, it is the angle with the tangent to the earth's surface, and this angle is the solar altitude angle. The greater the altitude angle of the sun, the more heat per unit area shines on the ground, and the less we know. For example, when you illuminate the ground with a flashlight at night, the brightness of the illuminated part of the ground is high if it is direct, and the brightness of the illuminated part of the ground is weak if you obliquely illuminate the light of the flashlight on the ground. This is the same as the change of solar altitude angle on the ground heat. Because the earth is a sphere, the higher the latitude, the smaller the solar altitude angle and the less solar heat it receives. On the contrary, the lower the latitude, the greater the solar altitude angle, and the more heat the ground receives. There is another variable in the solar altitude angle, which is also related to the direct point of the sun (the solar altitude angle of the direct point is 90? The closer the earth's surface is to the direct point in the longitudinal direction, the larger and smaller the solar altitude angle is. As far as a cylinder is concerned, the solar altitude angle decreases from north to south. Due to the influence of these two main factors, the temperature varies with latitude and season. Of course, there is a thick atmosphere outside the earth, which will also affect the heat of the sun reaching the ground. The smaller the altitude angle of the sun, the longer the distance the sun passes through the atmosphere, the stronger the radiation of the atmosphere to the sun, and the less the heat reaching the ground. On the contrary, the greater the solar altitude angle, the shorter the distance for the sun rays to reach the ground, the less radiation from the atmosphere to the sun, and the more heat reaching the ground, which is also a factor affecting the temperature, but the main factor is still the influence of the solar altitude angle on the ground.